Recrystalised grain morphology in 9Cr 1Mo ferritic steel

Grain morphology in cold rolled, recrystallize-annealed 9Cr 1Mo commercial grade ferritic steel has been investigated. The recrytallization-annealing up to 100 h at 1100 K exhibited carbide particles embedded in α-ferrite grain matrix. The resulted grain sizes were much smaller than those of virgin sample. The heat treatment more than 100 h resulted in dual phase ferrite-martensite morphology. The recrystallization-annealing at 1300 and 1350 K changed the morphology in complete tempered martensite microstructure significantly. The hardness of martensite structure was more than that of the ferrite. The 80% cold rolled samples resulted in increase in tensile strength with significant loss in ductility after recrystallization-annealing and air cooling.